SAO PAULO — The last time Rafael Nadal won in Brazil, it was at the very start of the most dominant clay-court career tennis has ever seen.

Eight years later, Nadal hopes his second title here will mark the restart.

Nadal beat David Nalbandian 6-2, 6-3 in the final of the Brazil Open on Sunday, his first trophy since returning from a seven-month layoff to treat his left knee.

While this indoor clay-court tournament is much more low-priofile than those he has grown used to winning, Nadal thrust his arms into the air and pumped his fist after Nalbandian sent a shot long to give the Spaniard his 51st singles title.

His second also came in this event in 2005, when he was still relatively unknown, and he went on to win the first of his seven French Open titles months later.

“Brazil will always be in my heart,” Nadal said. “Big things started to happen after I won here in 2005 and hopefully this is the start of something good again.”

Nadal needed the lengthy layoff to treat a partially torn and inflamed tendon in his knee, and his comeback was then further postponed by an illness. He returned to play in Chile last week, losing in the final of both the singles and doubles tournaments.

So lifting a trophy again felt extra good this time.

“I’ll definitely enjoy this one because of all the problems that I’ve gone through with the knee,” Nadal said. “When I won for the first time here I was just starting and hopefully this will mark a new beginning.”

It was Nadal’s first title since winning the French Open for the seventh time last June. Thirty-seven of his titles have been on clay.

Nadal struggled to find a rhythm in the beginning but was still able to break Nalbandian’s serve twice to take the first set, then rallied from 3-0 down in the second to win six straight games and close out and match in 1 hour, 18 minutes.

Seeking his 12th title, the 93rd-ranked Nalbandian was playing in a final for the first time since he was disqualified for kicking an advertisement board and injuring a line judge at Queen’s Club last June. The former world No. 3 hasn’t won a title since 2010 in Washington.

Nadal said his knee felt better on Sunday and it made all the difference.

“When the knee is feeling better like today I feel like that I can do more of the things that I used to do my entire life,” he said. “If the pain is bearable like it was today, then it’s fine.”

He had complained of soreness in his knee after Friday’s semifinal, which marked his second three-set match at the tournament.

Nadal still looked far from his best on Sunday, though, and didn’t seem to be moving well. The knee visibly bothered him at times and he left many balls unchallenged throughout the match.

But with the support from the local fans and with former Brazil star striker Ronaldo and mixed martial arts champion Anderson Silva in the crowd, Nadal took control of the match in the second set to secure the victory.

Nadal converted five of his eight break points against Nalbandian and was broken twice by the Argentine.

Nadal took the lead for the first time with a break in the sixth game, and then broke Nalbandian again in the final game to close out the set. The Argentine came out strong in the second set and broke Nadal twice in a row to go up 3-0, but the Spaniard quickly rebounded with two breaks and then cruised to close out the match without losing another game in front of nearly 10,000 people packing the Ibirapuera arena.

“I didn’t play my best match today, Rafa was much better,” Nalbandian said. “I was ahead in the second set but I couldn’t take advantage of it.”

The final in Brazil was only Nadal’s eighth singles match since his return.

He withdrew from the doubles in Sao Paulo after winning the first match with Nalbandian as his partner. Nadal said he wanted to rest his knee for the singles tournament.

The 11-time Grand Slam champion admitted that the level of the competition in Brazil was not as high as in other tournaments but said that it wasn’t bad either, giving him the perfect opportunity to give his knee a good test. The Spaniard will play another clay-court tournament in Mexico in two weeks.

“Right now I’m just thinking about celebrating this title, it means a lot to me,” Nadal said. “I still need time, so I’m thinking day-to-day, week-to-week.”

Nadal had won four of his six career matches against Nalbandian, the last one a three-set victory in the quarterfinals of Indian Wells last year. Nalbandian’s last victory over Nadal was in 2007 in the final of a Master Series tournament in Paris.

The 31-year-old Argentine made his season debut in singles at the Brazil Open. He was out of action for several months last season because of an abdominal injury.